Code Zero - Racing Spinnakers

AWA 45-70°

AWS 1-12 kts

Mid Grith 75% of foot

Light Code Zero Laminate

Rulemakers know that genoas are the most powerful sails for upwind work; therefore, the greater the area of a genoa, the higher a boat’s rating. Under the current design formulas, it pays to have large fractional mainsails and non-overlapping headsails. The Achilles heel of non-overlapping headsails is light air performance when sailing on a close reach. Creative sailmakers got around this conundrum by coming up with the Code Zero.

This picture illustrates how flat a Code Zero is.

Code Zeros are a must for distance racing on modern boats with non-overlapping headsails. Boats with small jibs are at a major disadvantage when jib reaching -- conditions when it is too close to carry a spinnaker, but the boat is not hard on the wind. Boats with overlapping genoas can get a lot more speed when they ease out their big genoas and they have the option of changing to an overlapping high-clewed jib top. Boats with non-overlapping jibs don't have enough sail area for reaching.

These pictures of an A35 show how much bigger the code zero is than the No. 1 jib

Hence the Code Zero was invented. These sails are more than twice the size of a non-overlapping genoa, are flat like a genoa, but they measure into a boat's inventory as a spinnaker. The code zero takes the place of a high-clewed overlapping jib top.

For a code zeros to measure in as a spinnaker, the mid girth needs to be at least 75% of the foot length.

Even the sailcloth used is a cross between spinnakers and genoas. A true Code Zero is made out of a laminate, with a few widely space aramid yarns. Code Zero cloth weigh between 2-3 ounces per yard.

Furler Options

There are three different methods for controlling a Code Zero. For boats 33 feet and smaller, sails are small enough that a furler is not necessary. For mid-sized boats 33-44 feet, a simple direct furler is the best option; for boats over 42 feet, you'll need a top-down furler to handle the Code Zero, which is getting quite big. There are many different companies making innovative furling units for Code Zeros. Talk to your local UK Sailmakers representative to find out which one will work best for your boat and budget.

Top-Down furlers work better with large Code Zeros and asymmetrical spinnakers because they roll up the roach and upper leech first. By rolling up the top of the sail first, the rest of the sail becomes blanked by the mainsail and as a result rolls up very tightly. Having a tight roll allows the sail to unroll better and a tight roll presents less windage so that it can be raised sooner without hurting your sailing performance.